<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <!-- 兼容IE-->
    <script>document.createElement("myElement")</script>
    <style>
        myElement{
            display: block;
            background-color: #2d2d30;
            color: white;
            padding: 60px;
            font-size: 30px;
            font-weight: bold;
            text-align: center;
        }
    </style>
</head>
<body>
    <myElement>这是自定义标签 &lt;myElement&gt;的显示效果</myElement>
</body>
</html>